Broach



1'. OAKLEY. BRoAcH. APPLlCATlON FILED APR.19, 1921.V v

Patente@ @still-1922.

2 SHEETS-SHEET l.

mami@ J. OAKLEY; BROACH. APPLLcAmoN man APR.19. 1921.

l ABQAW; Patented 001:. 17,1922

2 SHEETS-SHEET 2.

' INVENTOR.

STATES staan@ PATENT BROACH.

Application led April 19,

To all whom t may concern.'

Be it known that l, J'oHN OAKLEY, a subject of the King of England, anda resident of Springiield, in the county of Hampden and State ofh/iassachusetts, have invented a new and useful Breach, of which thefollowing` is a specilication.

My invention relates te improvements in breaches for cutting internal.slots or grooves, and consists essentially of a divided or slotted shankhaving therein a longitudinal, chip-clearance passage or passages, whichopen interiorly into the slot in said shank, and exteriorly through theperiphery and the rear end et the shank, a cutter bar provided on one erboth longitudinal edges with teeth, said bar being receivable 'in saidslet, adapted to have'the row or rows of teeth project beyond saidshank, and having lateral, chip-clearance passages between said teethand extending inwardly at an incline to open into said First-namedchip-clearance passage or passages, and means to tasten or secure saidbar in place in said shank, all as hereinafter set forth.

In many if not most cases, the teeth oit this breach, with the exceptionof one or more teeth at the rear end, are slabbed oftq on alternatesides, se that each oi such teeth cuts only a little more than one-halfof the width er' the slot which it assists in forming,

One object of my invention is to produce a breach oi' this character atthe minimum cost, yet enc which is strong, durable, accurate, andeiiicient. This is accomplished by forming a plurality of teeth from asingle bar on one er both longitudinal edges thereof, cutting therequired chip-clearance passages in said bar and in the shank, anduniting the bar with the shank in such a manner that exact alignment ofthe teeth and proper projection of the same are obtained. All of thework of making this breach can be done with the expenditure ofcomparatively little time, labor, and money, when other types ofbreaches for a similar purpose are considered.

The cutter bar can be readily removed from the shank for regrinding, orfor the substitution of another bar therefor, as may be desired. Teethconstructed in this manner, that is to say, as integral parts of a bar,can be easily and accurately reground, much more so, in fact, than canindependent 1921. Serial No. -62,523

or separable teeth on the one hand, er teeth that are integral with theshank in which there is no separable bar, on the other hand.

Other objects and advantages will appear in the course of the followingdescription.

l attain the objects and secure the advantages of my invention by themeans illustrated in the accompanying' drawings, in which- Figure l is atop plan et 'a breach, the central portion et the same being broken out,which embodies a `practical form of my invention; Fig. 2, a sideelevation of said breach, breken out in the center as before; Fig. 3, arear end elevation et the breach; Fig, el, a cross section through thebreach, taken on lines 4 4, looking in the direction of the associatedarrow, in F ig. 2; F ig. 5, a cross section on lines 5-5, looking` inthe direction of the associated arrow, Fig. 2; Fig. 6, a rear endelevation et a breach having a single row et teeth; F ig. 7, a similarelevation, showing a slight modilication; F ig. 8, a top plan similar tothe first view, except that the shank is made up et' separate,independent, or separable members, and, Fig. 9, another similar planillustrating a slightly di'erent shank made up of separate, independent,or separable members.

The right-hand end oit the breach, as it appears in the drawings, is thetrent end thereof, regardless as te whether the breach be pulled throughthe work, as is the more usual procedure, or be pushed or forced throughtrom behind, inasmuch as the leading and least projecting' tooth orteeth of the breach are the right-hand teeth, and the teeth project moreand more as the rear end of the breach is approached.

r)The terms top, bottom, and side, or equivalent terms, apply te thebreach as it is represented in the drawings, and would not always beapplicable to the same as it might be disposed for some kinds oi'l werkor in certain machines.

The breach illustrated in the first five views, which breach hasoppositely-disposed rows of teeth, comprises a ene-piece shank l whichhas at the front end a puller or screw-threaded projection 2 by means ofwhich the shank is attached to the machine in which the same isemployed, and is longitudinally slotted, centrally, from the rear end toa point a short distance trom said front end, as at 3, and recessed inopposite sides of the periphery, from said rear end to points which maybe a little in advance of the transverse plane at the closed end oi'said slot, to form diametrically-opposite, chip-clearance passages 6 6,and a cutter bar 7 provided on both longitudinal edges with teeth whichwill presently be described in detail, there being obliquely-transverse,chipeclearance passages 8 in said barbetvveen the teeth in each set.rIhe passages 8 in both sets have the saine direction of inclinationlaterally, consequently such passages in one longitudinal edge of thebar open into the passage 6 on that side, and such passages 8 in theother longitudinal edge of the bar open into the passage G on theopposite side. The passages 8 also have a rearward inclination, or theirrear sides or edges have such an inclination, the saine correspondingwith that is longitudinally of the rake of the teeth.

Suitable means niust be provided. lier securing the bar T in place inthe slot in thevshanlr 1, and causing the slotted portions of said shanktightly to einlaface said bar. Such means preferably consists oi aplurality of screws 9 and taper pins i0, all extending transverselythrough the slotted portions of the shank 1 and through the bar 7, saidscrews being` tapped into said shank, and said pins being driven intosaid shank and through said bar. The screws 9A and the pins 1() mustnot, ot course, pro trude at any point roin the openings therefor 'inthe periphery of the slotted portions of the shank 1. Upon unscreivingand removing the screws 9, and driving out the ins 10, the release ofthe bar 7 is eil'ected, and the latter can be reinoved from the shank 1.Then the sanne shank or another is inserted in the slot 8, and thescrews 9 and pins 10 are returned to place.

As previously stated, one or more of the rear teeth in the row on. cachlongitudinal edge ol the bar 7 are wide teeth. that is to say, thecutting edge o1" each oi" said teeth is of the saine Width as that ofthe slot which said row is designed to cut, While the cutting edges oitthe other 'teeth in the saine roware narrower, so that each is less inwidth than theividth or' said slot. The wide teeth are represented bythe numeral 11 and the narroiv teeth by the numeral l2. Each tooth l2 orits cutting edge is inade narrower by beveling or slabbing oli one,corner thereof, as represented at 18. Every other tooth 12 in each rowis slabbed oil on the same side. and the teeth between are all slabbedolii on; the opposite side, so that the cutting edge of one tooth is inoifset relation to the cutting edge oli the tooth which leads or'follows the sanne, although the cutting edges ol;l all of the teethextend invardiy lironithe sides ol" the bar 7 or ot said teethv beyondthe' major central plane of said bar. By thus extending the cuttingedgel of lirst one tooth 12 from one side of the bar 7 inwardly beyondthe longitudinal center or said bar, and of the next tooth from theopposite side of said bar inwardly beyond said center, each tivoadjacent teeth cut a slot oit the required vvidth, the cutting edges ofsuch teeth combined being commensurate with the cutting edge olf eithertooth 11. Adjacent pairs of the teeth l2 in a roiv Whichhave the oil--sent cutting edges may have the saine amount of projection, or the'following tooth may project slightly more than thev pre# ceding tooth,as may be desired, since the slots cuty by these teeth are finallyiinished by the tooth 11 in said roiv iat-the rear end oi the breach. lnthe present case there is only one tooth 11 on each longitudinal edge ofthe bar 7; y i

By locating the chip-clearance passages 6 on opposite sides ofi' the bar7, instead of both on the sanne side oli said bar with thechip-clearance passages 8 in said bar' delivering into the-in, thebroach hasa more balanced operation, and is capable 'of cutting slotsWithout chattering, with less liability on the part of the teeth togetout of alignment, and to better advantage generally.

ln practice, as the broa'ch is 'forced through the bore in a piece ofWork, tivo oppositely-disposed slots are cut in the sides oit said boreby the teeth 1Q and 11,v such teeth cutting deeper and deeper the ullWidth of the slots as the broach advances, and said 'teeth 11 finallycomplet-ing the slots and. removing any unevenness that may have beenlett .in the innermost sides thereot. Thus the slots are cut to therequired depth and Width. The chips cut vby the teeth 1,2 pass down the-faces' of the teeth and inwardly and laterally through the pas sages 8to the passages 6 on opposite sides of the barv8, and through saidlast-named 'passages to escape at the rear end oic the shank 1. 1

The principal objectk of slabbing oli"` the teeth 12 at 18 is to limitthe Width of the chips cut by said teeth, so that they can escape easilythrough the passages 8 into the passages 6 Without clogging or having atendency to tear or otherwise injure the adjacent lportion of the stockwhich is being slotted.l Each tooth 12 cuts a chip Which is onlyslightly Wider than one-half of the width ot the slot being cut,consequently sai d chip easily passes through the channels provided inthe broach for its escape during the broaching operation, Whereas, ifthe chip avere of the full Width, trwould be liable not only to clogsuch channels, but also to scrape against the edge of the slot beingeut, which edge in the 'latter case Would be in. the path ott the'chipas it passed from the lateral channel inwhich the chip is firstreceived, into the longitudinal channel which next receives the chip.

In each of Figs. 6 and 7, a cutter bar is represented at 14, which has arow of teeth on one longitudinal edge only, the rearmest tooth 1l ofsuch row appearing. Such being the case, only one longitudinal.,chipclearance i'iassage' in the shank 1 is needed. Otherwise theseconstructions are the same as the hrst, except that in the Fig. 7construction there is a slot 15 which extends only part way through theshank 1, insteady of all the way through the shank, like the slot 2 ineach of the other examples, so that a support is afforded for the bottomor inner, .longitudinal edge of the bar 14. The obliquely-transverse,chip-clearance passages 5 are present in each bar 14, as before. Theoperation ef either of the breaches having a single row of teeth ispractically the same as that of the breach having two rows, eX- ceptthat only one slot is cut with the former, instead of two as with thelatter.

The shank l, instead of being made in a single piece, may be constructedout of two er more pieces which are securely fastened together as shownin Figs. S and 9, and to which the bar T (or 111) is securely attached.la slet for such bar being provided in all cases.

ln Fig. S the shank 1 therein shown consists in part of a section 16which is initially separate from and independent of the other portion ofsaid shank. The section 16 is rigidly and securely attached to the otherportion of the shank by means of the screws 9 and pins 10 which fastenthe cutter bar T (or le) in place, and one or more additional screws asmay be required. rlihis section is set into one side of the otherportion of the shank, and with its inner face forms one side of the slot3 (or 15) for the cutter bar 'T (or 14)n The rear end of the section 16is flush with the rear end of the other portion of the shank, but, whilethe front end of said section extends forwardly beyond the correspondingend of the slet 3 (or 15), it does not extend far enough to form anypart of the front end of the shank.

in Fig. 9 the shank 1 is made in two sections of equal dimensionsdivided on a plane, indicated by the line 17, which extends from thelongitudinal center of the front end of the slot (or l5) forwardly tothe front end of the puller head 2. One or more additional screws 9 areprovided in this as in the previous construction.

The construction in other respects and the operation of the breachesshown in the last two views are the same as has hereinbefore been fullydescribed. and explained.

.it is to be understood that the term slot or slotted as herein used,relates to the slet which is provided in the shank to receive the cutterbar, regardless of the manner in which said slot is produced, since themanner of producing the same in a shank comprising originally separateand independent parts would be different from that in a shank consistingof a single piece.

More or less change in the shape, size. construction, and arrangement ofseme or all of the parts of this breach, besides the modicationsillustrated and described herein in detail, may be made withoutdeparting from the spirit of my invention or exceeding the scope of whatis claimed.

1 am aware that stationary holders have been employed through whichtooth-pro vided bars or breaches have been drawn, but such aconstruction necessitates the use of a very much longer and a very muchweaker breach than is the breach herein presented, and the werk dene bythe fermer is liable to be less accurate than that dene by the latter.

W hat l claim as my invention, and desire to secure by Letters Patent,is`

1. As an improved article'of manufacture, a breach comprising a shankhaving an eX- terier longitudinal chip-clearance passage therein, a barprovided with teeth on a longitudinal edge thereof, and having lateralchip-clearance passages therein between said teeth, which last-namedpassages open inte said first-named passage, said shank being slotted toreceive said bar, and means to secure said bar in place in the slot insaid shank.

2. As an improved articleof manufacture, a. breach comprising a shankhaving exterior longitudinal chip-clearance passages therein, a barprovided with teeth en the opposite longitudinal edges thereof, andhaving lateral chip clearance passages therein between said teeth, whichlastnamed passagesvopen into said first-named passage, said shank beingslotted to receive said bar, and said irst-named passages being onopposite sides of said bar, and means to secure said bar in place in theslet in said shank.

3., As an improved article ef manufacture, a breach comprising a shankhaving an exterior longitudinal chip-clearance passage therein, a barprovided with teeth on a longitudinal edge thereof, and having lateralchip-clearance passages therein between said teeth, which last-namedpassages open into said first-named passage, said shank being solid atthe leading terminal and there provided with a puller projection, andslotted back of said terminal to receive said bar, and removable meansto secure said bar in place in the slot in said shank.

4L. As an improved article of manufacture,

a breach comprising a shank having an exterior longitudinal.chip-clearance passage therein, a bar provided with a single row ofteeth on a longitudinal edge thereof, certain of said teeth beingslabbed off to narrow their cutting edges, and said bar having lateralchip-clearance passages therein between said teeth, which last-namedpassages open into said first-named passage, said shank being slotted toreceive said bar, and means to secure said bar in place in the slot insaid shank.

5. Aas an improved article of manufacture, a broach comprising a shankhaving an ei:- terior longitudinal chip-clearance passage therein, a barprovided with a single row 'of teeth on a longitudinal edge thereof,certain of said teeth being slabbed off on one side, and certain othersof said teeth being slabbed oit on the other side, to narrow theircutting edges, and said bar having lateral chipclearance passagestherein between said teeth, which last-named passages open into said{irst-named passage, said shank being slotted to receive said bar, andmeans to secure said bar in place in the slet.

6. As an improved article of manufacture, a broach comprising a shankhaving an eX- terior longitudinal chip-clearance passage therein, a barprovided with a single row of teeth ,on a longitudinal edgethereot,.crer tain ot said teeth being slabbed off to provide cuttingedges which are narrower than the full width of the slot cut by thebreach, and arranged so that some of such edges entend 'from onedirection beyond the longitudinal center of said bar, and others of suchedges extend from the opposite direction beyondsaid center, and said barhaving lateral chip-clearance passages therein between said teeth, whichlast-named passages open into said rst-named passage, said shank beingslotted to receive said bar, and means to secure said bar in place inIthe slot in said shank. t l

7. As an improved article of manufacture, a. broach comprising a shankhaving an eze terior longitudinalv chip-clearance passage therein, a barprovided with a single row of teeth on a longitudinal edge thereof,certain of said teeth being slabbed oft to provide cutting edges whichare narrower than the full width of the slot cut by thebroach, and

arranged so that every other of said cutting edges extends from onedirection beyond the longitudinal center of said bar, and the Outtingedges between extend from the opposite direction beyond said center, andsaid bar having lateral chip-clearance passages therein between saidteeth, which last-named passages open into said first-named passage,said shank being slotted to receive said bar, and means to secure saidbar in place in the slot in said shank.

8. As an improved article of manufacture, a broach comprising acentrally-slotted shank having therein diametrically-oppositelongitudinal chip-clearance passages which are en opposite sides yof theslot in and open through the periphery of said shank, a bar receivablein said slot and provided with a single row of teeth on the oppositelongi tudinal edges thereof, certain oil-' said teeth being slabbed offon thel outside to narrow their cutting edges, the slabbed portions ofevery other of such teeth being on the one side and the slabbed portionsof such teeth which are between being on the other side, and said barhaving lateral chip-clearance passages therein between said teeth, whichlast-named passages open into said rstnamed passages` and means tosecure together said shank and bar.

9. As an improved article of manufad ture, a breach comprising a shankhaving an exterior longitudinal chip-clearance passage therein, a b arprovided with a single row of teeth on a longitudinal edge thereof,certain of said teeth being slabbed off on the sides to provide cuttingelges of less width than that of the slot to be cut, and arranged sothat such cutting edges are in offset relation to each other, and saidbar having lateral chip-clearance passages therein between said teeth,which lastnamed passages open into said first-named passage, said shankbeing slotted to receive said bar,

and means to lsecure said bar in place in the slot in said shank.

JOHN OAKLEY. Witnesses:

A. C. FAIRBANKS, F. A. CUTTER.

